Patek Philippe - Grandmaster Chime Ref. 5175

A watch fit for a king. It was our first thought when we saw the star of the collection of commemorative timepieces created by Patek Philippe to celebrate its 175th anniversary: the Grandmaster Chime Reference 5175.

Without doubts one of the world's most elaborate wristwatches and not only to the number of complications involved but also to the horological degrees of complexity, the new Patek Philippe Grandmaster Chime is also the first double-face wristwatch presented by Patek Philippe that can be worn with either dial facing up: the one that focuses on the time and the sonnerie, the other dedicated to the full instantaneous perpetual calendar. The reversing mechanism integrated the lugs allows the wearer to easily change the face.

A Patek Philippe's master engraver invested several hundred hours of work to decorate the red gold case, adorning it with relief engravings of a special anniversary laurel foliage motif and with a sharp burin chisels the inscriptions and symbols that explain the functions of the operating elements into the caseband.

The double-face case has a diameter of 47 mm and accommodates four spring barrels, two of them double reserved for the strikework and minute repeater mechanisms, and a total of not less than 20 complications:

When the crown of the watch points to the right, the owner sees the dial that apart from local time also indicates the time in a second time zone together with a day/night indication. The same dial features the power-reserve indicators for the movement and strikework barrels, the position of the winding crown (winding, alarm setting, hand setting), the selection of the strikework mode (Grande Sonnerie, Petite Sonnerie, or Silence) as well as a bell-shaped aperture for the alarm ON/OFF display and a small round window for the strikework isolator (disabled/enabled) display.

The dial of the calendar face features four subdials with analog displays grouped around the gold-framed four-digit year display in the middle. The month is indicated at 3 o'clock, the date and leap-year cycle at 6 o'clock and the day of the week at 9 o'clock. The time of day appears at 12 o'clock on the 24-hour and 60-minute sundial.

The current time and the perpetual instantaneous date - the most frequently consulted information - are displayed on both dials.

To protect complicated timepieces against damage caused by inadvertent manipulations, the manufacture's engineers devised clever "isolators" that interrupt the flow of power between individual mechanisms or block certain functions while others are active.

The effort invested by Patek Philippe in this unique anniversary timepiece is impressive. More than 100,000 hours were logged for development, production, and assembly, of which 60,000 hours for the components of the movement.

Each calibre consists of 1,366 parts and each case of 214 separate parts, bringing the total number of components for each Grandmaster Chime to the mind-boggling number of 1,580!

The Patek Philippe Grandmaster Chime celebrates the 175th anniversary of the manufacture in a limited edition of seven watches. Six of them will be sold to long-standing collectors of Patek Philippe timepieces. The seventh one will be on display at the Patek Philippe Museum. The price? 2.5 million Swiss Francs.

Patent: Alarm mechanism with time strikeMechanism that acoustically indicates a preset alarm time with hour, quarter-hour, and minute strikes using the chiming mechanism of the minute repeater.Patent: Isolation of the Grande Sonnerie in the Silence modeMechanism that totally uncouples the Grande Sonnerie from the movement when the Silence mode is selected, eliminating friction and thus power consumption.Patent: Selection of strikework operating modeMechanism that allows the automatic time strike to be selected or disabled with a single slide switch: Grande Sonnerie, Petite Sonnerie or Silence. Formerly, two separate switches were needed to make these settings.Patent: Date repeaterMechanism that obtains date information from the perpetual calendar and forwards it to the repeating mechanism. Manufacture president Thierry Stern is the inventor.Patent: Reversible wristwatch caseWristwatch case with rotating and latching devices in the lugs, allowing it to be turned along the axis from 12 to 6 o'clock and locked in either of 2 positions.Patent: Mechanism for a four-digit year displayMechanism that automatically synchronizes the four-digit year display with the leap-year cycle and allows convenient correction of both displays in either direction.Innovation: The strikework differentialAn innovative masterpiece of micromechanical engineering (not patented): the differential between the strikework double barrels and the two strikework mechanisms for the Grande Sonnerie (incl. minute repeater and alarm) and the date repeater. It has a diameter of 7.2 mm and consists of 19 separate parts, one of which is an 11-part ball bearing with 7 balls with a diameter of 0.3 mm each. Despite its small size, it is robust enough to transmit the torque of the strikework barrels which exceeds 1700 gmm.
The video below gives an idea of the process that brings to the creation of a masterpiece like the Patek Philippe Grandmaster Chime Ref. 5175.